Automobile trunks are today most commonly locked by means of a key operated cylinder lock mounted within an opening in the trunk lid outer wall which has a lock stem that extends inwardly into a rotatable keyway of a latch housing that is operatively linked with the trunk latch. Thieves and pilferers however all too often break into such trunks by inserting a wedge shaped tool or screwdriver between the cylinder lock and its lid mount and exerting leverage on the lock. In this manner the cylinder lock may either be forced inwardly or pried outwardly from the trunk lid. In the event the thief is successful in prying the cylinder lock outwardly the rotatable keyway will become exposed through the now vacant opening in the trunk lid. The thief may then easily insert an elongated tool such as a screwdriver through the lid opening and into the rotatable keyway and rotate the keyway key and thus operate the latch. Alternatively, in the event the thief is successful in forcing the cylinder lock inwardly the lock may then fall downwardly pulling the lock stem with it out of the keyway and similarly exposing the rotatable keyway through the vacant opening in the lid.
In order to prevent the aforementioned action of thieves automobile trunk lock security devices have been heretofore provided such as those disclosed in U.S. Pat. Nos. 3,740,980 and 4,041,741. In the former patent a tubular sleeve constructed of a durable material is mounted so as to encase the cylinder lock stem and the opening in the latch mechanism. In the latter patent an inner and outer plate is sandwiching about the exterior wall of the trunk lid about the periphery of the cylinder lock. The outer plate inhibits one from punching a hole in the trunk lid in the vicinity of the lock to manipulate the latch while the inner plate inhibits one from punching the lock inwardly. These devices, however, may be rather easily circumvented. For example, the provision of a tubular sleeve about the lock stem does not inhibit one from prying the cylinder lock outwardly. In such an event the sleeve merely accompanies and rides upon the lock stem until it either falls off of the stem or is itself pulled out with the lock through the trunk lid opening. The provision of two plates sandwiches about the inner and outer surfaces of the trunk lid wall fails to inhibit one from taking a tool and twisting the entire lock cylinder itself thereby causing the trunk latch to operate. Furthermore, the presence of a plate on the exterior of the trunk often proves unattractive in appearance.
Accordingly, it is a general object of the present invention to provide an improved automobile trunk lock security device.
More specifically, it is an object of the invention to provide a security device for a cylinder lock mounted to an automobile trunk lid.
Another object of the invention is to provide a security device of the type described which bidirectionally inhibits axial movement of the cylinder lock.
Yet another object of the invention is to provide a security device of the type described which is of simple and economic construction and which may be readily mounted in place.